ml
86 lines
2.0 KiB
Go
86 lines
2.0 KiB
Go
package resource
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import "io/ioutil"
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// Store holds a set of resources. This set can be modified.
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type Store struct {
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ids []ID
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resources map[ID]*Resource
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}
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// IDs returns a list of available IDs this store currently contains.
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func (store Store) IDs() []ID {
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ids := make([]ID, 0, len(store.resources))
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for _, id := range store.ids {
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if _, existing := store.resources[id]; existing {
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ids = append(ids, id)
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}
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}
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return ids
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}
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// Resource returns reference to the contained resource for given identifier.
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func (store Store) Resource(id ID) (*Resource, error) {
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res, existing := store.resources[id]
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if !existing {
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return nil, ErrNotFound(id)
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}
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return res, nil
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}
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// View returns a read-only view on the resource for given identifier.
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func (store Store) View(id ID) (View, error) {
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return store.Resource(id)
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}
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// Del removes the resource with given identifier from the store.
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func (store *Store) Del(id ID) bool {
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_, existing := store.resources[id]
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if existing {
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delete(store.resources, id)
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}
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return existing
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}
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// Put (re-)assigns an identifier with data. If no resource with given ID exists,
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// then it is created. Existing resources are overwritten with the provided data.
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func (store *Store) Put(id ID, view View) error {
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data := make([][]byte, view.BlockCount())
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for index := 0; index < len(data); index++ {
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reader, err := view.Block(index)
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if err != nil {
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return err
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}
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data[index], err = ioutil.ReadAll(reader)
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if err != nil {
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return err
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}
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}
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res := &Resource{
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Properties: Properties{
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Compound: view.Compound(),
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ContentType: view.ContentType(),
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Compressed: view.Compressed(),
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},
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Blocks: BlocksFrom(data),
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}
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if store.resources == nil {
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store.resources = make(map[ID]*Resource)
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}
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store.resources[id] = res
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if store.findIDIndex(id) < 0 {
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store.ids = append(store.ids, id)
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}
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return nil
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}
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func (store Store) findIDIndex(id ID) int {
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for index := 0; index < len(store.ids); index++ {
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if store.ids[index] == id {
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return index
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}
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}
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return -1
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}
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